Find out what weapon it came out of and look at Numrich Arms/Gun Parts on the Internet.
They have an abundance of original parts most of the time. Also as a last resort if you have a Lowe's or Menards close they have screws that may be similar in the bolt, screws section usually in individual metal door trays.
The Constitution is not an instrument for the Government to restrain the people. It is an instrument for the people to restrain the Government!
“Americans have the right and advantage of being armed. Unlike the people of other countries, whose leaders are afraid to trust them with arms.”
James Madison. Author of the 2nd Amendment